Depends on cooling and air circulation in your case, which is unique to every pc case, but most of gtx 460 can be set to 1.087v and clocked to hell and back. That is really temps that are gonna stop you.That's what i did with my two msi cyclone 768 mb version: set the volts to max, the up the core until it is giving errors when folding. Turn out the two of them stops at 910 core. They never crossed the 80c bar. They are now under water, and i've tried up to 1,3 v on them, only to get to the 950 zone. Really not worth the gpu's vrm burning my fingers!